"""Persistent shared-key quota: new cookies and worker restarts cannot reset it."""

import sqlite3
import time
from contextlib import closing

from .protocol import DecisionError


class HostedBudget:
    def __init__(self, path, hourly=60, daily=600):
        if not 1 <= hourly <= daily <= 10000:
            raise ValueError("invalid_hosted_budget")
        self.path, self.hourly, self.daily = str(path), hourly, daily
        with closing(sqlite3.connect(self.path)) as db, db:
            db.execute("CREATE TABLE IF NOT EXISTS calls (created REAL, weight INTEGER)")

    def reserve(self, weight=1):
        now = time.time()
        # Synchronous short transaction, no await between checking and reserving.
        with closing(sqlite3.connect(self.path, timeout=2)) as db, db:
            db.execute("BEGIN IMMEDIATE")
            db.execute("DELETE FROM calls WHERE created < ?", (now - 86400,))
            daily = db.execute("SELECT COALESCE(SUM(weight),0) FROM calls").fetchone()[0]
            hourly = db.execute(
                "SELECT COALESCE(SUM(weight),0) FROM calls WHERE created >= ?", (now - 3600,)
            ).fetchone()[0]
            if hourly + weight > self.hourly or daily + weight > self.daily:
                raise DecisionError("shared_budget_exceeded", 429)
            db.execute("INSERT INTO calls VALUES (?,?)", (now, weight))